Subject: Re: Beyond CL?
From: (Rob Warnock)
Date: Sun, 21 Aug 2005 22:18:11 -0500
Newsgroups: comp.lang.lisp
Message-ID: <>
Ray Dillinger  <> wrote:
| Rob Warnock wrote:
| > Another plus is that CHAR-CODE-LIMIT, the "upper exclusive bound on
| > the value returned by the function char-code", is an non-negative
| > INTEGER, not a FIXNUM, so while the occasional BIGNUM is ugly, it's
| > not forbidden.
| But you can't pick a finite value for char-code-limit with grapheme
| characters...

Just pick something "really big", big enough to encode enough
overstrikes to turn the whole grapheme solid black, e.g., maybe
whatever CHAR-CODE-LIMIT value could accommodate a character
composed of a 256 codepoint sequence, say.

| ...and there will be a bunch of integers between 0 and
| char-code-limit that don't correspond to any legitimate character.

No problemo, says the CLHS:

    Function CODE-CHAR
    code-char code => char-p
    Returns a character with the code attribute given by code.
    If no such character exists and one cannot be created,
    NIL is returned.

And likewise:

    Constant Variable CHAR-CODE-LIMIT
    The value of char-code-limit might be larger than the actual
    number of characters supported by the implementation.


Rob Warnock			<>
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